Apparatus for controlling flow of blood

ABSTRACT

A combination, including pressure regulating apparatus, for controlling the flow of blood in a limb of a patient characterized by a container of a biologically inert gas such as carbon dioxide at a pressure no more than 1,000 pounds per square inch gauge (psig), a pressure regulator means that provides a set downstream pressure without variation even under zero flow conditions and having a convenient means for altering the set downstream pressure, a gauge that reads in both psig and millimeters of mercury for medical use, a pressure relief means for relieving the downstream pressure back to atmospheric pressure, an inflatable tourniquet, and the requisite interconnections. Also disclosed are preferred embodiments; including a Beir block combination having a plurality of inflatable tourniquets for anesthetizing locally; and respective branches connecting with the pressure regulating apparatus, each branch incorporating a toggle valve means for allowing alternate and inverse tourniquet inflation and deflation with immediately responsive operation of the respective inflatable tourniquet in accordance with a doctor&#39;&#39;s orders without having to alter the setting on the pressure regulator means; as well as other specific structural and advantageous features.

[475] July 23, 1974 APPARATUS FOR CONTROLLING FLOW OF BLOOD [76]Inventor: Russel W. Shook, 521 Brookside Ter., Oklahoma City, Okla.73137 [22] Filed: Feb. 16, 1973 [21] Appl, No.2 333,399

Related US. Application Data [63] Continuation-impart of Ser. No.163,963, June 19,

1971, abandoned.

128/DIG.20, 297-299, 30-302; 137/505, 505.13, 613, 624.14

[56] References Cited UNITED STATES PATENTS 2,660,174 11/1953 Saemann.128/327 3,120,846 2/1964 Fletcher 128/337 OTHER PUBLICATlONS Journal ofBone & Joint Surgery, Vol. 36-A, No. 6, Dec. 1954, pp. 5 & 15 5 PrimaryExaminerCharles F. Rosenbaum Attorney, Agent, or Firm-Wofford, Felsman,Fails &

' Zobal [5 7 ABSTRACT A combination, including pressure regulatingapparatus, for controlling the flow of blood in a limb of a patientcharacterized by 'a container of a biologically inert gas such as carbondioxide at a pressure no more than 1,000 pounds per square inch gauge(psig), a pressure regulator means that provides a set downstreampressure without variation even under zero flow conditions and having aconvenient means for altering the set downstream pressure, a gauge thatreads in both psig and millimeters of mercury for medical use, apressure relief means for relieving the downstream pressure back toatmospheric pressure, an inflatable tourniquet, and the requisiteinterconnections. Also disclosed are preferred embodiments; including aBeir block combination having a plurality of inflatable toumiquets foranesthetizing locally; and respective branches connecting with thepressure regulating apparatus, each branch incorporating a toggle valvemeans for allowing alternate and inverse tourniquet inflation anddeflation with immediately responsive operation of the respectiveinflatable tourniquet in accordance with a doctors orders without havingto alter the setting on the pressure regulator means; as well as otherspecific structural and advantageous features.

9 Claims, 5 Drawing Figures PAIENIEUmzamn 3.825.008

SHEU 1 0f WQmw A TTORNEYS 1 APPARATUS FOR CONTROLLING FLOW OF BLOODcRoss REFERENCES TO RELATED APPLICATIONS:

This is a continuation-in-part of application Ser. no. 163,963, filedJuly 19, 1971, now abandoned.

BACKGROUND OF THE INVENTION:

1. Field of the Invention:

This invention relates to apparatus for controlling the flow of blood inthe limb of a patient. More particularly, it relates to a combination ofapparatus employing a pressurized gas and an inflatable tourniquet andpressure regulating and flow control means'therebetween. 7

2. Description of the Prior Art: 1

The prior art has seen the development of inflatable pneumatictourniquets such as described in US. Pat. No. 3,120,846. Thesetourniquets have employed pressurized oxygen from an oxygen container,since it is readily available in hospitals. These prior art apparatahave, suffered from one or more of the following disadvantages, however:v

l. the gas employed in the tourniquet has been dangerous since it wouldsupport combustion and has resulted in burns to the patient whencauterizing equipmentor the like was employed in conjunction with theinflatable tourniquet, as is sometimes done in operating rooms;

2. the pressure regulator means employed in controlling the pressure tothe inflatable tourniquet varied over an intolerably wide range of manymillimeters of mercury and even several pounds per square inch (psi)from one time of use to the next, and even with the same time of useunder zero flow conditions;

3. attempts to employ bottled gases other than oxygen in which the gaswas at a much higher pressure; for example, nitrogen bottles have apressure in excess of 2000 psi; resulted in intolerable variations inpressure downstream of the pressure regulator means;

4. the connections employed were not leak-free and allowed anintolerable change in pressure if the source instating the pressure whenneeded without altering the setting on the pressure regulator means.

The prior art apparatus has been particularly deficient in providingequipment facilitating a Beir block. In the Beir block, a dualtourniquet cuff, or two closely spaced inflatable tourniquets areemployed on a limb, such as an arm or leg, that is to be anesthetizedlocally. The Beir block is employed where the patient is physicallyunable to sustain a general anesthetic or the like. A local anesthethic,such as xylocaine, is injected sev eral times with alternate and inverseinflation and deflation of the respective tourniquets to anesthetize thearm or leg of an operation without imposing intolerable strain; forexample, on the patients heart. The Beir has been found so effectivewhen properly used by employing the apparatus of this invention, that itis much easier than a general anesthetic and is coming into morewidespread use. Heretofore, the Beir block with the prior art apparatusrequired difficultly controllable systems, including dualpressureregulating means, cuffs and separate valves that weredifficultly openable or closeable such that normal operating roompersonnel, without help, could not operate a Beir block satisfactorily.Thus, the Beir block required, before this invention, additionalcirculating nurses, requiring more people in the operating room andincreasing the likelihood of infection in an incision or the like.

Thus, it can be seen that the prior art apparatus did not providetotally satisfactoryequipment for controlling the flow of blood in thelimb of a patient; and, particularly, was deficient when it came toperforming a Beir block for anestheti'zing locally.

Accordingly, it is an object of this invention to provide apparatuswhich obviates the disadvantages of the prior art apparatus and providesthe desirable features antithetical to the disadvantages delineatedhereinbefore.

It is also an object of this invention to provide apparatus that isideally suited for performing a Beir block for locallyanesthetizing alimb of a patient and obviating the deficiencies of the prior art inthis respect.

These and other objects will become apparent from the descriptive matterhereinafter, particularly when taken in conjunction with the drawings.

BRIEF DESCRIPTION OF THE DRAWING(S):

FIG. 1 is a perspective view of the combination in accordance with oneembodiment of this invention.

FIG. 2 is a front elevational view of the pressure regulating apparatusof the embodiment of FIG. 1.

FIG. 3 is a partial plan view of the face of the gauge for downstreampressure in the embodiment of FIG. 2.

FIG. 4 is a partial isometric view of another embodiment of thisinvention that is ideally suited for performing a Beir block.

FIG. 5 is a partial front elevational view of the apparatus of FIG. 4.

DESCRIPTION OF PREFERRED embodiment(s):

Referring to FIG. I, the combination 11 includes a container 13 ofcarbon dioxide at a super atmospheric pressure of no more than 1,000pounds per square inch gauge (psig); pressure regulating apparatus 15for effecting controlled inflation of an inflatable tourniquet for useon the limb of a patient; flexible conduit 17; and an inflatabletourniquet 19. The combination 11 may be suitably supported andtransported on a mobile support frame 21 to facilitate movement to thedesired 10- cation.

As indicated, the container 13 contains carbon dioxide at a superatmospheric pressure of no more than 1,000 psig. The carbon dioxide isillustrative of a medically inert gas which does not react with tissueof a patient so is safe for use in the operating room, and iscommercially available in the desired pressure range; for example, inthe class E cylinders of C0 1 have found that commercially availablecontainers of carbon dioxide at pressures of from 600 to 900 psig effectoptimum results and comprises the preferred embodiment of thisinvention. Other medically inert gases could be specially bottled. andwould be the equivalent. For example, nitrogen could be speciallybottled for the desired pressure range. The present bottles of nitrogencontain too high a pressure; for example 2,250 psig; so are notequivalent in terms of obtaining the desired static downstream pressurefrom a pressure regulator means. As indicated hereinbefore, thecontainers of medically reactive gases such as oxygen are notsatisfactory because of the dangers posed in case there is a leak. Otherwell known bottled gases such as acetylene pose medical reactiondangers, have too high pressure and are explosive when admixed withcombustion supporting gases; and, accordingly, are not suitable for usewith the inflatable tourniquet.

The pressure regulating apparatus l5comprises the major essentialelements of a pressure regulator means such as pressure regulator 25 formaintaining a set downstream pressure; a first connection means such asconnector 27 for connecting the regulator 25 with container 13; a gaugemeans such as gauge 29 for monitoring the downstream pressure; apressure relief means such as relief valve 31 for relieving thedownstream pressure back to atmospheric pressure; and a secondconnection means such as sealing connector 33 for connecting the reliefvalve 31 with the inflatable tourniquet. In the preferred embodimentillustrated in FIGS. 1 and 2, the pressure regulating apparatus alsoincludes a toggle valve means such as toggle valve 35 for allowingrapidly relieving the downstream pressure on the inflatable tourniquetwithout altering the set downstream pressure on the regulator 25.Preferably, also, an inlet gauge 37 is provided for monitoring thecontent, or quantity of gas remaining in container 13.

The regulator 25 is a single stage compensated regulator that isdesigned for less than 1,000 psi inlet pressure and for maintaining theset downstream pressure within a few millimeters of mercury regardlessof whether or not there is flow through the regulator and regardless ofwhether or not the regulation is continuous or is interrupted by turningon and off a master valve 39 on the cylinder 13. The regulator 25 alsohas a convenient manually operable means such as the knurled handle 41for altering the set downstream pressure. These requirements onregulator 25 are stringent and not readily met. I have not been able toaccomplish these results with an inlet pressure in excess of 1,000 psig.Moreover, I have found that the regulator 25 requires a resilientneoprene seat to effect the desired sealin g at zero flow rate. It isimperative that the regulator employed in my pressure regulatingapparatus regulate at the desired pressure and return to the samepressure each time it is used. To accomplish this, not only is itnecessary to employ a resilient seat such as of neoprene to effectsealing of the inert gas, and to employ gas at a pressure of less than1,000 psig, but the resiliency and size of the diaphram is significant,as is the resiliency and shape of the needle seat and the shape of theneedle that is employed in the regulator. For example, l have found that(l) a 3 /2 inch diaphram is advantageous and (2) two springs, a mainregulating spring, and a resistance spring should be employed inconjunction with the pressure on the diaphram to effect the desiredduplicate regulation of zero flow rate. A suitable gauge that meets theforegoing stringent requirements is commercially available from AirProducts and Chemical Company, Medical Division, Allen- 4' town,Pennsylvania. Accordingly, the correlation setting forth the interactionof the recited elements in the regulator need not be described in detailherein, since the regulator is not being claimed, per se.

The connector 27 is a conventional connector that encompasses the master'valve 39. The connector 27 has a suitable resilient sealing means suchas an o-ring (not shown) adjacent the passageway leading to regulator 25via bushing 45. The connector 27 has suitable biasing means such asthreaded bolt 47 for forcing engagement of the sealing means with themaster valve 39 such that they effect fluid-impermeablesidewalls thatdefine a passageway and connection between the cylinder 13 and theregulator25.

The gauge 29 has a dial face having the equivalent markings of pressurein psi and in millimeters of mercury (mm Hg); as well as showing otherconvenient markings; such as, the average pressure required for shuttingoff the flow of blood through a limb such as an arm and a leg; tofacilitate medical use. As is well known, the pressure in millimeters ofmercury is the height of a column of mercury in vacuo as measured inmillimeters that is equivalent to the pressure. A typical dial face'49for the gauge 29 is illustrated in FIG. 3. Therein the pressure inmillimeters of mercury are indicated as millimeters of mercurialpressure. Any other recognized nomenclature may be employed. Asillustrated,the gauge 29 is screwed into a downstream body 53. that isconnected with the downstream side of regulator 25. I j

. The relief valve 31 is a conventional push button type relief valvehaving a relieving passageway and aperture that are normally sealed by apoppet seating on a suitable seat. The poppet may be pushed inwardly toopen the effluent passageway to vent the downstream pressure that isemployed to inflate the inflatable tourniquet. The venting isaccomplished exteriorly by depressing inwardly on a suitably biased pushbutton 51. Such relief valves are conventional and need not be describedin detail. It is sufficient to note that pressure is readily relieved byinward depression of the spring biased push button 51. Other forms ofrelief valves may be employed as long as they are rapidly andconveniently operable so that the nurse or other technician may rapidlycarry out the doctors instruction in an op.- erating room. Asillustrated, the relief valve 31 is connected with the body 53 viatoggle valve 35.

The toggle valve 35 is interposed intermediate the pressure regulator 25and the relief valve 31. The toggle valve 35 is a quick-opening valvehaving a two position toggle 57 for effecting respective on and offoperation so as to be rapidly responsive to operation in accordance withthe doctors orders in an operating room. That is, the toggle 57 may beflipped into the indicated off position to block pressure from regulator25 and allow the relief valve 3.1 to be opened by inward depression ofpush button 51, immediately relieving the pressure on the tourniquet. Inthe off position, however, the pressure downstream ofjthe regulator 25and upstream of toggle valve 35 is maintained such that the toggle 57may be flipped to the straight out, or on" position, to immediatelyrestore pressureto the inflatable tourniquet. These variations inpressure are effected without altering the setting of the regulator 25;and, therefore, does not require time-consuming subsequent adjustment-toobtain exactly the desired setting. The quick-opening feature of thetoggle valve 35 is effected by a relatively large area of poppet, inaccordance with well recognized principles of construction forquick-opening valves. The quick-opening type toggle valves arecommercially available; for example, from the supplier, delineatedhereinbefore, of regulator The sealing connector 33 comprises aconventional quick-connect" connector employing suitable o-ring andmating recess and protrusion means that are biased to effect the desiredseal. The sealing connector 33 is intimately associated with themating'portion on the flexible conduit 17. The flexible conduit 17 has asufficient length so that the container 13 of carbon dioxide can beplaced'at a desired location in an operating room, and the inflatabletourniquet placed on the desired limb of the patient. Ordinarily, alength of several feet is adequate. The flexible conduit 17 terminatesat its other end in a mating portion 59 for a suitable sealing connectorsuch as sealing connector 33. The Second sealing connector is emplacedon the inflatable tourniquet 19.

The inflatable tourniquet 19 may take any of the present commerciallyavailable forms of tourniquet, such as described in the hereinbeforereferenced U.S. Pat. No. 3,120,846. On the other hand, the inflatabletourniquet may be disposable cuffs such as the Zimmer or Kiddedisposable cuffs having the strips of adhesive over the outside insteadof the more expensive Velcro type fasteners employed with theconventional inflatable tourniquets. Since the inflatable touniquets 19are commercially available and the details are not claimed, per se,herein, no further detailed descriptionis necessary. It is sufficient tonote that the inflatable tourniquets operate to restrict the flow ofblood through the arteries and veins at respective pressures in responseto the downstream pressure effected by the regulator 25. It will bereadily apparent that conventional blood pressure determining bands maybe employed advantageously with the pressure regulating apparatus ofthis invention, as well as the other inflatable tourniquets.

The inlet gauge 37 is screwed into a suitable body (not shown) and influid connection with the inlet passageway for the regulator in order tomonitor the pressure and, consequently, the contents of the cylinder 13.This allows ensuring that there is a sufficient supply of gas in thecontainer 13 to carry out the desired manipulations of the inflatabletourniquet for any desired operation or the like.

I have found that it is imperative that the connections downstream ofthe regulator 25, and particularly downstream of toggle valve 35, beleak-free such that the toggle 57 may be operated into the off positionand the pressure on the inflatable tourniquet will be maintained. Thisrequires a high degree of care and testing in assembly. Otherwise, thedownstream pressure that is locked into the flexible conduit 17 by thetoggle valve will be lowered by leaks.

In operation, the inflatable tourniquet.l9is applied in the conventionalmanner to the limb of the patient. The mating portion 59 of the flexibleconduit 17 may be connected with the sealing connector of the inflatabletourniquet 19 before or after it is emplaced. Preferably, it ispre-connected and pre-tested for leaks, as indicated hereinbefore. Theknurled handle 41 is turned to increase the downstream pressure, asindicated on gauge 29, to effect the desired pressure in the inflatabletourniquet 19. In the event that the doctor desires to temporarilyrelieve the pressure, the toggle 57 may be moved to the illustrated offposition and the push button 51 depressed to relieve the pressure fromthe inflatable tourniquet. For example, a doctor might desire to providea flow of oxygen to prevent damaging cells during a protractedoperation. When pressure is again desired on the tourniquet, the toggle57 is flipped to the straight out, or on position and pressure isimmediately restored. The regulator may be adjusted to provide a newdownstream pressure by adjusting the knurled handle 41. If the pressureis lower, a momentary relief of pressure via relief valve 31 may beprovided by depression of push button 51.

Another embodiment of this invention is illustrated in FIGS. 4 and 5.Therein, a combination 7] comprises a source 73 of medically inert gasat a superatmospheric pressure of no more than 1,000 psig; pressureregulating apparatus 15 for effecting controlled inflation of aplurality of inflatable tourniquets employed on the limb of a patient;first connection means 75 connecting the pressure regulating apparatus15 with the source 73; gauge means 29; and a plurality of branches 77and 79 for controlling the flow of blood in the limb of a patient atdifferent locations. Each of the branches 77 and 79 include a seriallyconnected toggle valve 35 for connecting and disconnecting an inflatabletourniquet with the inert gas at the downstream pressure set on thepressure regulating apparatus 15; pressure relief valve 31 for relievingthe downstream pressure back to atmospheric pressure; fittings andconduit means, such as flexible conduit means 17, for connecting aninflatable tourniquet with the pressure regulating apparatus 15, and aninflatable tourniquet means 19- forputting pressure on veins andarteries within a limb of a patient for controlling the flow of bloodtherein. The combination 71 may be suitable supported and transported onamobile support frame 21 to facilitate movement to the desired location.As illustrated, the mobile support frame 21 comprises a bracket that maybe hung by suitable means, such as hook 81, on suitable support, such asthe intravaneous (IV) support pole 83. As is known, the IV support pole83 is connected .to any suitable support in an operating room or thelike, illustrated generically by the support lines 84. Thus, thecombination 71 is readily transportable into any operating room or toany table within a large operating room.

The source 73 of medically inert gas may comprise any source delineatedhereinbefore, such as the carbon dioxide container. As illustrated, itcomprises a source of carbon dioxide or nitrogen that ispiped into anoperating room at a regulated pressure of about 160 psig. Specifically,containers of the carbon dioxide or nitrogen are located at a remotepoint, such as the basement. High pressure regulators are connected withthe containers and the piping to supply the medically inert gas at thedesired pressure. As described hereinbefore, the medically inert gas hasa pressure less than 1,000 psig; and observes the caveats describedhereinbefore with respect to the source of high pressure fluid.

The pressure regulating apparatus 15 is, in principle, the same asdescribed hereinbefore. Mainly, it employs the same pressure regulator25. The pressure regulating apparatus 15 is not connected with acylinder by means of the connector 27, FIG. 1, and, consequently, thatportion of the descriptive matter is not pertinent.

Instead, the first connection means 75 comprises an elongate flexibleconduit 85 that has a regulator con- 7 nection fitting 87, FIG. 5,connecting it with the pressure regulator 25 at one end and a male quickdisconnect fitting 89 for stabbing within the quick disconnectreceptacle at the outlet to the source 73 of the medically inert fluid.The flexible conduit 85 may be of any length. Ordinarily, a length ofabout 25 feet is satisfactory to reach between a convenient outlet ofthe source 73 and the pressure regulator 25 at the IV support pole 83 atthe patients'operating table (not shown) in the operating room. Any ofthe conventional types of flexible' conduit 85 that will sealingly holdthe medically inert fluid against its pressure; for example, up to'1,000 psig; may be employed.

The gauge 29, the relief valve 31 and the toggle valve 35 have beendescribed hereinbefore. As can be seen, the respective toggle valve 35and relief valve 31 are serially connected together and with thepressure regulator 25 by conventional fittings such as threadedconnections or the like. As illustrated, each pressure relief valve 31is connected via an elbow 91 with the flexible conduit 17. Each of therespective flexible conduits 17 and their sealing connectors have beendescribed hereinbefore and need not be repeated.

Similarly, each of the inflatable tourniquets 19 have been-describedhereinbefore.

The same high degree of care is employed in connecting togetherthe-plurality of branches with their respective Y-fitting 93, gauge 29and pressure regulator 25, as has been described hereinbefore withrespect to the single branch of FIGS. 1 and 2.

In operation, the pressure regulator 25 is connected with the source 73of high pressure, medically inert fluid by way of first connection means75. The frame 21 is hung on the IV support pole 83, or other suitablesupport. Inflatable tourniquets 19 and 19A are emplaced at the desiredpoints on the limb, such as leg 95, of the patient. The tourniquets 19and 19A of the respective branches 77 and 79 are sealingly seriallyconnected with the single pressure regulator 25. As indicatedhereinbefore, it is preferable that the tourniquets have beenpre-connected and pre-tested for leaks. The knurled handle 41 is turnedto effect the desired downstream pressure as indicated on gauge 29. Asillustrated in FIGS. 4 and 5 first one tourniquet and then the other isinflated with the opposite tourniquet being deflated at the same time.Thus, the tourniquets are alternately and inversely inflated anddeflated for effecting the Beir block. As illustrated, the toggle valve35A is on, allowingthe downstream pressure to be supplied to theinflatable tourniquet 19A while the toggle valve 35 is turned of byhaving its toggle flipped laterally into the horizontal, or of position.In the first branch 77, pressure is relieved by having depressed thepush I button 51 on the relief valve 31, deflating tourniquet 19. Next,the toggle valves 31 and 31A will be reversed I to inflate theinflatable tourniquet 19; and by depressing push button 51A, deflate theinflatable tourniquet 19A. By this alternate and inverse inflation anddeflation, in combination with injection of a local anesthetic, the limbmay be anesthetized locally without giving the patient a generalanesthetic with the attendant strain on the heart or the like. Thiscombination 71 has been found doubly beneficial, since it allows use ofonly a single pressure regulator means without the expense of aplurality of pressure regulators; and it eliminates the work and thedifficulty of achieving the same pressure in the respective inflatabletourniquets.

Moreover, the usual operating room personnel can be employed to rapidlyflick the respective toggle handles of the toggle valves 35 and 35A intotheir respective on and off positions for effecting the alternate andinverse inflating and deflating of the tourniquets 19 and 19A. Sincefewer personnel are required in the operating room, there is lessproblem with sterilizing the atmosphere and there are, consequently,less infections that result from use of the combination 71 than withconventional apparatus.

Thus, it can be seen .that this invention has wide usefulness andaccomplishes the objects set out hereinbefore, and has great practicalutility and commercial importance. Moreover, this invention has become asignificant tool in the fight to improve health care and reducecomplications from operations on patients.

The materials of constructionwhich are ordinarily employed in this artmay be employed herein, and no exotic new materials are necessary. Adegree of care, as indicated, is-necessary in assembly and in theconstruction of the regulator 25.

Although this invention has been described with a certain degree ofparticularity, it is understood that the present disclosure is made onlyby way of example and that numerous changes in the details ofconstruction and the combination and arrangement of parts may beresorted to without departing from the spirit and the scope of thisinvention.

What is claimed is:

1. A combination for controlling the flow of blood in a limb of apatient comprising:

a. a container of carbon dioxide at a super atmospheric pressure of nomore than 1,000 pounds per square inch gauge (psig);

b. a pressure regulator means for maintaining a set downstream pressure,said pressure regulator means being a single stage compensated regulatorthat is designed for less than 1,000 psig inlet pressure and formaintaining said set downstream pressure within a few millimeters ofmercury pressure and without variance even under no flow conditions;said pressure regulator means also having a convenient manually operablemeans for altering said set downstream pressure;

0. first connection means connecting said pressure regulator means withsaid container of carbon dioxide;

(1. gauge means connected with the downstream side of said pressureregulator means for monitoring the downstream pressure, said gauge meanshaving a dial face being marked in pounds per square inch and inmillimeters of mercury for medical use;

e. pressure relief means connected with the downstream side of saidpressure regulator means and adapted for relieving said downstreampressure back to atmospheric pressure;

f. a toggle valve means interposed intermediate said pressure regulatormeans and said pressure relief means and connected therewith forallowing rapidly relieving the pressure on an inflatable tourniquetwithout altering the downstream pressure set on said pressure regulatormeans;

g. inflatable tourniquet means for putting pressure on veins andarteries within the limb of the patient for controlling the flow ofblood therein; and

h. flexible conduit means connected with and extending between saidpressure relief means and said inflatable tourniquet means.

2. The combination of claim 1 wherein said flexible conduit hassufficient length so that said container of carbon dioxide can be placedat a desired location in an operating room and said inflatabletourniquet emplaced on the desired limb of the patient, and said togglevalve means is a quick-opening valve having a two position toggle foreffecting respective on and off operation so as to be rapidly responsiveto operation in accordance with a doctors orders in an operating room.

3. The combination of claim 1 wherein the elements connected with thedownstream side of the pressure regulator means are pre-assembled andpre-tested to have leak-free connections such that when said togglevalve is shut off, the pressure in said inflatable toumiquet ismaintained.

4. Pressure regulating apparatus for effecting controlled inflation ofan inflatable tourniquet for use on the limb of a patient comprising:

a. a pressure regulator means for maintaining a set downstream pressure,said pressure regulator means being a single stage compensated regulatorthat is designed for less than 1,000 psig inlet pressure and formaintaining said set downstream pressure within a few millimeters ofmercury pressure and without variance even under no flow conditions;said pressure regulator means also having a convenient manually operablemeans for altering said set downstream pressure;

b. first connection means for connecting said pressure regulator meanswith a container of carbon dioxide at a super atmospheric pressure of nomore than 1,000 psig;

0. gauge means connected with the downstream side of said pressureregulator means for monitoring the downstream pressure thereof, saidgauge means having a dial face marked in pounds per square inch and inmillimeters of mercury for medical use;

d. pressure relief means connected with the downstream side of saidpressure regulator means and adapted for relieving said downstreampressure back to atmospheric pressure;

e. a toggle valve means interposed intermediate said pressure regulatormeans and said pressure relief means and connected therewith forallowing rapidly relieving the pressure on said inflatable tourniquetwithout altering the downstream pressure set on said pressure regulatormeans; and

f. second connection means for connecting said pressure relief meanswith an inflatable tourniquet.

5. The apparatus of claim 4 wherein said toggle valve means is aquick-opening valve having a two position toggle for effectingrespective on and off operation so as to be rapidly responsive tooperation in accordance with a doctors orders in an operating room.

6. The apparatus of claim 4 wherein the elements connected with thedownstream side of the pressure regulator are pre-assembled andpre-tested to have leak-free connections such that when said togglevalve is shut off, the pressure in said inflatable tourniquet ismaintained.

sure within a few millimeters of mercury pressure and without varianceeven under no flow'conditions; said pressure regulator means also havinga convenient manually operable means for altering said set downstreampressure;

c. first connection means connecting said pressure regulator means withsaid source of medically inert gas; d. gauge means connected with thedownstream side of said pressure regulator means for monitoring thedownstream pressure, said gauge means having a dial face being marked inmillimeters of mercury for medical use; and e. a plurality of branchesconnected with the downstream side of said pressure regulator means,each branch including:

i. a toggle valve means connected with the downstream side of saidpressure regulator means; said toggle valve means being a quick openingvalve and having a toggle handle that is easily flipped into either theon or the of position for rapidly and easily connecting anddisconnecting an inflatable tourniquet with the inert gas at thedownstream pressure set on said pressure regulator;

ii. pressure relief means connected with the downstream side of saidtoggle valve means; said pressure relief means having externallyaccessible, manually operable means for facilitating immediatelyrelieving pressure manually for deflating a tourniquet means;

iii. inflatable tourniquet means for putting pressure on veins andarteries within the limb of the patient for controlling the flow ofblood therein; and

iv. flexible conduit means connected with and extending between saidpressure relief means and said inflatable tourniquet means;

whereby the inflatable tourniquet means in the branches can bealternately and inversely inflated and deflated with only one pressureregulator and gauge and only normal operating room personnel withoutrequiring additional personnel in the operating room and attendantincrease in the likelihood of infection. 8. The combination of claim 7wherein said gauge means, said toggle valve means and said pressurerelief valve means are connected with the downstream side of saidpressure regulator means and are preassembled and pre-tested at thefactory to have leak-free connections when distributed to hospitals.

9. The combination of claim 7 wherein an inlet gauge is provided incommunication with the inlet to said pressure regulator means formonitoring the pressure of said source of medically inert gas.

1. A combination for controlling the flow of blood in a limb of apatient comprising: a. a Container of carbon dioxide at a superatmospheric pressure of no more than 1,000 pounds per square inch gauge(psig); b. a pressure regulator means for maintaining a set downstreampressure, said pressure regulator means being a single stage compensatedregulator that is designed for less than 1,000 psig inlet pressure andfor maintaining said set downstream pressure within a few millimeters ofmercury pressure and without variance even under no flow conditions;said pressure regulator means also having a convenient manually operablemeans for altering said set downstream pressure; c. first connectionmeans connecting said pressure regulator means with said container ofcarbon dioxide; d. gauge means connected with the downstream side ofsaid pressure regulator means for monitoring the downstream pressure,said gauge means having a dial face being marked in pounds per squareinch and in millimeters of mercury for medical use; e. pressure reliefmeans connected with the downstream side of said pressure regulatormeans and adapted for relieving said downstream pressure back toatmospheric pressure; f. a toggle valve means interposed intermediatesaid pressure regulator means and said pressure relief means andconnected therewith for allowing rapidly relieving the pressure on aninflatable tourniquet without altering the downstream pressure set onsaid pressure regulator means; g. inflatable tourniquet means forputting pressure on veins and arteries within the limb of the patientfor controlling the flow of blood therein; and h. flexible conduit meansconnected with and extending between said pressure relief means and saidinflatable tourniquet means.
 2. The combination of claim 1 wherein saidflexible conduit has sufficient length so that said container of carbondioxide can be placed at a desired location in an operating room andsaid inflatable tourniquet emplaced on the desired limb of the patient,and said toggle valve means is a quick-opening valve having a twoposition toggle for effecting respective on and off operation so as tobe rapidly responsive to operation in accordance with a doctor''s ordersin an operating room.
 3. The combination of claim 1 wherein the elementsconnected with the downstream side of the pressure regulator means arepre-assembled and pre-tested to have leak-free connections such thatwhen said toggle valve is shut off, the pressure in said inflatabletourniquet is maintained.
 4. Pressure regulating apparatus for effectingcontrolled inflation of an inflatable tourniquet for use on the limb ofa patient comprising: a. a pressure regulator means for maintaining aset downstream pressure, said pressure regulator means being a singlestage compensated regulator that is designed for less than 1,000 psiginlet pressure and for maintaining said set downstream pressure within afew millimeters of mercury pressure and without variance even under noflow conditions; said pressure regulator means also having a convenientmanually operable means for altering said set downstream pressure; b.first connection means for connecting said pressure regulator means witha container of carbon dioxide at a super atmospheric pressure of no morethan 1,000 psig; c. gauge means connected with the downstream side ofsaid pressure regulator means for monitoring the downstream pressurethereof, said gauge means having a dial face marked in pounds per squareinch and in millimeters of mercury for medical use; d. pressure reliefmeans connected with the downstream side of said pressure regulatormeans and adapted for relieving said downstream pressure back toatmospheric pressure; e. a toggle valve means interposed intermediatesaid pressure regulator means and said pressure relief means andconnected therewith for allowing rapidly relieving the pressure on saidinflatable tourniquet without altering the downstream pressure set onsaid pressure regulator means; and f. second connecTion means forconnecting said pressure relief means with an inflatable tourniquet. 5.The apparatus of claim 4 wherein said toggle valve means is aquick-opening valve having a two position toggle for effectingrespective ''''on'''' and ''''off'''' operation so as to be rapidlyresponsive to operation in accordance with a doctor''s orders in anoperating room.
 6. The apparatus of claim 4 wherein the elementsconnected with the downstream side of the pressure regulator arepre-assembled and pre-tested to have leak-free connections such thatwhen said toggle valve is shut off, the pressure in said inflatabletourniquet is maintained.
 7. A combination of apparatus for controllingflow of blood in a limb of a patient and facilitating anesthetizing thelimb locally, comprising: a. a source of medically inert gas atsuperatmospheric pressure of no more than 1,000 pounds per square inchgauge (psig); b. a pressure regulator means for maintaining a setdownstream pressure, said pressure regulator means being a single stagecompensated regulator that is designed for less than 1,000 psig inletpressure and for maintaining said set downstream pressure within a fewmillimeters of mercury pressure and without variance even under no flowconditions; said pressure regulator means also having a convenientmanually operable means for altering said set downstream pressure; c.first connection means connecting said pressure regulator means withsaid source of medically inert gas; d. gauge means connected with thedownstream side of said pressure regulator means for monitoring thedownstream pressure, said gauge means having a dial face being marked inmillimeters of mercury for medical use; and e. a plurality of branchesconnected with the downstream side of said pressure regulator means,each branch including: i. a toggle valve means connected with thedownstream side of said pressure regulator means; said toggle valvemeans being a quick opening valve and having a toggle handle that iseasily flipped into either the ''''on'''' or the ''''off'''' positionfor rapidly and easily connecting and disconnecting an inflatabletourniquet with the inert gas at the downstream pressure set on saidpressure regulator; ii. pressure relief means connected with thedownstream side of said toggle valve means; said pressure relief meanshaving externally accessible, manually operable means for facilitatingimmediately relieving pressure manually for deflating a tourniquetmeans; iii. inflatable tourniquet means for putting pressure on veinsand arteries within the limb of the patient for controlling the flow ofblood therein; and iv. flexible conduit means connected with andextending between said pressure relief means and said inflatabletourniquet means; whereby the inflatable tourniquet means in thebranches can be alternately and inversely inflated and deflated withonly one pressure regulator and gauge and only normal operating roompersonnel without requiring additional personnel in the operating roomand attendant increase in the likelihood of infection.
 8. Thecombination of claim 7 wherein said gauge means, said toggle valve meansand said pressure relief valve means are connected with the downstreamside of said pressure regulator means and are preassembled andpre-tested at the factory to have leak-free connections when distributedto hospitals.
 9. The combination of claim 7 wherein an inlet gauge isprovided in communication with the inlet to said pressure regulatormeans for monitoring the pressure of said source of medically inert gas.